The report goes on to break out various effects for different categories based on a sliding scale according to the amount of temperature increase. The table from the original report is reproduced in Illustration 5. A close inspection reveals a mixed bag of results.
Illustration 5: Figure SPM-1 from the AR4 WGII Summary.
Take food production, for instance; some areas are hurt because of drought while others may see increased productivity. As discussed in later chapters, moderate global warming may actually benefit some areas due to greater rain-fall and higher agricultural production.
The impact on wildlife is also mixed. Some species will have expanded ranges while others may go extinct. Coral seems to have a particularly bleak future. If the deep ocean currents that transport heat around the globe weaken, the effects are unpredictable. These currents are called the meridional overturning circulation (MOC), also referred to as the thermohaline circulation or the “great ocean conveyor belt.”
The Causes of Global Warming
What are the causes of the rise in temperature? There are a number of possible causes or contributing factors listed in AR4. Climate scientists refer to the causes as forcing factors or forcings. The forcings identified by the IPCC's fourth report are shown in Illustration 6.
Notice that the factors are shown in order of their “level of scientific understanding,” from left to right. By level of understanding the IPCC means how confident they feel that their conclusions are correct. If we apply the confidence level definitions from Table 2, the true meaning of this illustration becomes clear. The only forcing factor given a high level of confidence is the leftmost column in the greenhouse gases section. IPCC scientists claim to be 80% confident that they understand the effects of the gases listed in this column, the major one being CO2. The other two columns in this section are devoted to ozone, O3.
Illustration 6 Causes of climate change according to the IPCC. Source IPCC.
Ozone gets two columns because it can either cause warming if it appears in the troposphere (the lower atmosphere), but can cause cooling if it is present in the stratosphere (part of the upper atmosphere). Either way, the confidence in understanding is rated medium, only five in ten. It's a coin toss that the IPCC scientist's knowledge is correct.
The remaining nine forcing factors are rated low or very low. Understanding of eight of the twelve categories shown are rated as having less than a one in ten chance of being correctly interpreted. So, using the IPCC's own figures and confidence scale, they really only have high confidence in their understanding of less than 10% of the causes of global warming. They admit to not understanding 75% of the causes they list.
Interestingly, the cooling effects shown almost cancel out the warming effects if you add them all up. Notice how the possible cooling effect of aerosols alone could cancel most of the greenhouse gas effect. The bars for the poorly understood factors are drawn as simple lines, not broad distinctive bars. This purposefully obscures their possible impact. Since all of the cooling effects are given low levels of certainty, they have been mostly ignored.
This lack of understanding of the fundamental factors of climate change explains why the case for global warming presented to the public always focuses on greenhouse warming. To further simplify the presentation, carbon dioxide, the largest part of the greenhouse gas column, becomes the cause. And because humans emit large amounts of CO2 into the atmosphere the case is complete—our planet is threatened by human-caused global warming.
Global Climate Models and CO2
A 1.8°F temperature rise is lower than future temperature forecast by the IPCC. The IPCC has predicted a range of future temperature increase of 2.0°-11.5°F.40 Rather than simply estimating future temperature increase from the past trend, the IPCC relies on global climate models (GCM).41 These models are complex computer programs that have been under development for several decades. Using these models, climate scientists try to simulate the effects of various environmental factors on global climate. Of the many predictions made by these models, the result that gets the most attention is, of course, temperature.
The complexity of modeling global climate is addressed in best seller, “The Skeptical Environmentalist,” by author Bjørn Lomborg:
“Essentially, answering the question about temperature increase from CO2 means predicting the global temperature over the coming centuries—no mean feat, given that Earth's climate is an incredibly complex system. It is basically controlled by the Earth's exchange of energy with the sun and outer space. The calculations comprise five important basic elements: the atmosphere, the oceans, the land surface, the ice sheets and the Earth's biosphere.”42
Because Earth's climate is amazingly complex, modelers try to find a minimum of input parameters to simplify their programs. Fewer inputs make the programs easier to write and debug. Simpler models also take less computer time to run. A successful model accurately captures the effects of all the important inputs to a system and ignores the unimportant ones.
For a model to be considered accurate it must undergo a process called validation. Validation compares a model's results with real world measurements from the past, a process called backcasting. During validation, scientists set the values of the input variables to a known state. The model is adjusted (called tweaking or tuning) until the outputs of the model match the known answers for the initial conditions.
But, as modelers will tell you, a model can always be adjusted to give the right output values for a single set of test conditions.43 Passing validation, or even making one successful prediction, is no guarantee that the model is correct, or that it will provide accurate future predictions. As modeling experts have stated, “in complex natural systems, successful prediction of one event doesn't mean that it will work the next time the model is applied.”44
Knowing they are on shaky scientific ground, the IPCC doesn't rely on a single model. Their figures are the results of hundreds of different scenarios, each based on different assumptions. Perhaps this is done with the hope that hundreds of unsupportable answers will, by sheer luck, stumble upon a correct one. Even that doesn't really matter. The IPCC reports are written by hundreds of authors, modified by hundreds of reviewers, and then submitted to a committee of political representatives for a final edit. The numbers in the IPCC reports are those that are politically acceptable. Politics have created consensus science.
Climate modelers have been tweaking their programs for decades, trying to get their models to produce valid answers. As stated, models of Earth's climate are extremely complex. The more complex the system being modeled, the more complex the model, and the longer it takes to get good results. Accordingly, many modeling teams have simplified their models by choosing a dominant input—carbon dioxide. Because computer models are at the heart of the IPCC's climate predictions, and because the GCMs are being driven primarily by atmospheric CO2 levels, we must examine why this should be so. The subjects of CO2 induced greenhouse warming and computer climate models will be covered in detail in later chapters.
A Summary of the Problem
In total, the consequences of global warming are rather moderate, at least at the lower end of the temperature increase scale. The IPCC data does not support the strident warnings of impending disaster portrayed in some media stories. Increase in storm activity, famine, drought and epidemics are mentioned but not given prominence. The more extreme effects are only likely to happen if Earth's temperature rises by more than a few degrees over the next century.
As stated earlier, science is not based on political consensus. It is based on real data and provable facts. Unfortunately, the truth about global warming has been obscured by a number of exaggerated, dumbed down, sensationalized claims made mostly by non-scientists for reasons that have nothing to do with the scientific search for knowledge.
Here are the facts that are not in dispute:
Since around 1850, Earth has been experiencing a general warming trend with temperatures rising about
1.8°F (1°C) per century.
Human beings are adding large amounts of carbon dioxide to the atmosphere each year by burning fossil fuels that have remained buried in the Earth for hundreds of millions of years.
Carbon dioxide in the atmosphere has a warming effect on the planet as a whole.
Those are the facts, everything else is speculation. All the projected apocalyptic disasters are based on rising temperatures, with the worst damage requiring the most drastic temperature elevation. In turn, the temperature predictions are based, not on empirical evidence, but on CO2 driven computer climate model programs.
As we will see, these computer programs are incomplete, error prone stand-ins for real experimental science. This fact is well known by the IPCC and the scientists working on the climate modeling programs. Unfortunately, the inaccuracy of climate models is seldom discussed in the media. An exception is this statement in New Scientist:
“Most modelers accept that despite constant improvements over more than half a century, there are problems. They acknowledge, for instance, that one of the largest uncertainties in their models is how clouds will respond to climate change. Their predictions, which they prefer to call scenarios, usually come with generous error bars.”45
All a model can do is project our present, limited understanding of Earth's climate into the future. There is no way for climate scientists to test their theories about global warming directly. The only way to do that would be to have a second Earth to run experiments on. Perhaps in the distant future mankind will become so powerful that we can use planets as playthings, but for now, this is only fantasy. Scientists are left having to wait for the passage of time to prove them right or wrong. The best that can be done is to make rational projections based on how Earth's climate has acted in the past.
Filling the gap between what science can and cannot prove is global warming hysteria, manufactured by a scientifically illiterate press urged on by a cadre of special interest groups. Every cause that can possibly establish a link to global warming has done so because that ensures they will get media attention. If you are anti-industrialist, anti-globalist, anti-American, or even vegetarian, the smart move is to jump on the global warming bandwagon. Politicians and celebrities, instinctive seekers of publicity, are totally captivated.
How do the people who work on these IPCC reports see their task? In the words of Chairman R. K. Pachauri, “we are privileged to perform by bringing together the world’s best experts and scientists on an ongoing basis to serve you and to serve the interests of the human race and all life on this planet.”46 A noble sentiment, but high-minded ideals are meaningless if the results of your work are distorted, or used improperly.
The Working Group III (WGIII) report on “mitigation” states that “with current climate change mitigation policies and related sustainable development practices, global GHG47 emissions will continue to grow over the next few decades.”48 In Chapter 17, we will discuss suggestions in the WGIII report that addresses lowering Earth's temperature. One important point to know is that greenhouse gas levels will not stabilize for 100-150 years. This IPCC conclusion is the result of running 177 simulation scenarios. The most aggressive scenarios are based on negative emissions of greenhouse gases, achieved using technologies that don't currently exist.
The only way to significantly reduce greenhouse gas emissions right now is to ban the automobile and severely curtail industrial activity worldwide. As hard as this would be on people in developed countries, it would be devastating for underdeveloped nations. Other “cures” proposed by NGOs and special interest groups, such as respecting indigenous peoples, reducing third-world infant mortality, and empowerment of women, while they may be good and noble ideas, have nothing to do with Earth's climate warming.
In the following chapters we will contrast the case made by the IPCC with other theories and opinions expressed by scientists. Despite claims of consensus, many scientists do not agree with the IPCC reports. We will examine Earth's past to see if the current “crisis” is, in fact, unprecedented. We will also determine how much credibility we should give the prophets of doom.
An examination of climate changes in the past, cooling periods as well as warming periods, might tell us something about the forces controlling Earth's temperature. If the current warming trend proves to have historical precedents, particularly during times when Man wasn't adding sizable amounts of greenhouse gas to the atmosphere, then we may gain some insight into the major causes of climate change happening now.
In the next chapter we will examine climate changes in the recent past. We will look back over history, both recorded and from before humans learned to write. Back to a time when the glacial ice sheets retreated northwards, ushering in the relatively warm period we are in today. To understand our present climate we must understand the ice age we live in.
We are in an Ice Age?
“Well, why don't they call it The Big Chill? Or The Nippy Era? I'm just sayin', how do we know it's an Ice Age?”
— Macrauchenia #1 in the movie Ice Age
An ice age is a period when Earth's climate cools, leading to the formation of persistent ice sheets, called glaciers, at the poles and on continental land masses. The current ice age has been going on for the last 3 million years. In the movie Ice Age, the question was posed, “how do we know it's an ice age?” The answer given was “because of all the ice!” Scientists who study glaciers, glaciologists, would agree. They consider any time period when there are permanent, year-round ice sheets in both the northern and southern hemispheres, to be an ice age. That includes the really cold periods, as well as the warmer ones. During the past 3 million years, there have been times when there has been less ice than the present, and times when there has been much, much more.
The Iceman
Around 3300 BC, a lone traveler struggled to make his way across an alpine mountain pass. His joints ached from the cold, caused by what modern people call arthritis. Hunger was beginning to gnaw at him, the last time he had eaten was more than eight hours earlier. That had been a good meal of deer meat, grain and fruit. He had not realized when he set out on the journey that it was to be his last.
A well-dressed resident of the bronze age, the traveler wore a cloak made of woven grass with a vest, a belt, and a pair of leggings. Underneath was a loincloth and on his feet were shoes, all made of leather. On his head was a bearskin cap with a leather chin strap. The shoes were waterproof and wide, seemingly designed for walking across the snow. Their soles were made of bearskin for added traction with deer hide top panels and a netting made of tree bark. Within the shoes, soft grass wrapped his feet like warm socks.
Illustration 7: Ötzi the Iceman.
His belt had a sewn pouch that contained his personal possessions: a scraper, a drill, flint flakes, and tinder for starting a fire. A copper axe with a yew handle, a flint knife, a quiver of arrows with dogwood shafts. Only two of the arrows were finished, twelve were not. A three foot (1 m) yew longbow, unstrung, rounded out his kit. The traveler was well-armed and able to defend himself. According to blood traces found on his clothes and weapons, the bronze age man had recently killed or injured at least four other people. Unfortunately, they were not the only ones injured.
A deep wound in the man's hand throbbed and the arrow he had taken in the back had bled him almost to unconsciousness. He had pulled out the arrow shaft but the head remained stuck in his shoulder. He reached the top of the pass, almost 10,000 ft (3200 m) above the valley, but was exhausted and weakened from bleeding. He could go no further. Stacking his possessions neatly on a snow bank, the traveler sat down, bowed his head and died. He had lived about 46 years—he was to remain buried in the ice for 5,300 years.
The traveler was found by two German tourists, Helmut and Erika Simon, on September 19, 1991. His ice-preserved body was found in the Ötztal valley in Italy, less than 100 yards from the Austrian border. At first, the body was thought to be a modern corpse, like several others that had re
cently been found in the region. In the Alps, people have been known to die in accidents and become encased by the ice. When it was discovered that the victim dated to pre-historic times he was christened Ötzi the Iceman by the news media.
What prompted the Iceman to leave the hospitable valley below the pass, with no food or water to speak of, and try to cross the mountain at a time of year when several feet of snow obscured the steep, rocky Alpine ridge remains a mystery. It is known that he died from the arrow wound. At first, it was thought that he might have been the victim of a hunting accident. The discovery of other evidence strongly suggests that he was harried to his death by enemies. He must have escaped his attackers or he would not have had his weapons. Above all, he had his precious bronze axe with him when he died alone in the mountain pass. Perhaps the killers attacked and the Iceman managed to fight back, wounding or driving them off before escaping into the mountains. We will never know for sure.
We do know from finding the Iceman's body, and his well-preserved possessions, that thousands of years before the rise of the Roman empire, there were people traveling over passes in the Alps. They were well-dressed for the weather and able to use trails that only recently have become passable to hikers again. Ötzi is called the Iceman, but he lived during a time when Europe's climate was as warm as today's.
We are in what scientists call an interglacial period, a time of warming when the ice sheets around the world retreat. The current interglacial is called the Holocene. The last glacial period, a time when ice sheets advance, ended about 12,000 years ago. Illustration 8 shows the variation in average temperature over the past million years. For most of that time it was much colder than the present day, indicated by the dashed line, but it has also been hotter than the present on several occasions.
The Resilient Earth: Science, Global Warming and the Fate of Humanity Page 4
